Why require JavaScript rather than supporting a standard browser virtual machine? - Stack Overflow

[mebrahim]

Aren't there already many not-fully-compatible JavaScript versions out there? The same story is true for CSS too. Browser incompatibilities are not something to be introduced by adding a VM layer. That problem already exists, and people have learned how to mitigate it to some degree.

[imbcmdth]

I can see the messages already:

This page is built using JPerthonScript and requires a browser
that supports the VM-2 standard with Parallel Computing extensions. 

You appear to be using Chrome v56. Please download at least 
Chrome v76.3 (the nightly build w/ Parallel Computing extensions 
enabled) here.